Generally, in laboratory centrifuges rotors are used which are embodied as drum rotors or swing-bucket rotors and rotate around a vertical rotational axis.
U.S. Pat. No. 2,821,339 A discloses a laboratory centrifuge, wherein a rotor is rotated with a low rotational speed around a rotational axis having a horizontal orientation. Here, the rotor is directly held by a drive stud of an electrical drive. The rotor is formed by a drum with a hollow cylindrical drum wall. On the side facing towards the drive the drum is closed by a supporting plate having the shape of a circular disc. The drum is open on the side facing away from the drive. A plurality of mounts for vessels with the probes being centrifuged are held at the drum wall, wherein the mounts are dispersed in circumferential direction and nested into each other. Here, the mounts are formed by spring clips which are formed by two spring arms having an orientation in radial inner direction and which open in inner direction in the shape of a V. It is possible to insert the containers from the open side of the drum in a direction parallel to the rotational axis of the rotor between spring arms of a mount or between adjacent spring arms of two neighboring mounts. In this way, the container is clamped by the spring arms. Here, the longitudinal axis of the container has an orientation parallel to the rotational axis of the rotor. A lid or closure of the container is located on the side facing away from the drive. It is possible that a plurality of drum walls having differing diameters is concentrically nested. In this way, it is possible to increase the number of containers centrifuged by the rotor.
The publication US 2008/0182742 A1 discloses a centrifuge, wherein a plurality of rotors having the shape of circular discs rotate around a common horizontal rotational axis. By a common drive or a plurality of individual drives it is possible to drive the rotors in common. However, it is also possible that during the continued centrifugation with other rotors one rotor is decoupled from the at least one drive. Probes that have already been centrifuged are removed from this rotor and the rotor is then equipped with a new probe with subsequent restart of the driving of the rotor with the associated drive. In this way, it is not required to interrupt a centrifugation by a single rotor or a plurality of rotors when loading or unloading another rotor. It is possible to displace the rotor transverse to the rotational axis in order to uncouple the rotor from the driving connection, e.g. a driving drum. A loading and unloading of a rotor is accomplished by a loading and unloading device. Via a rail the loading and unloading device is displaceable parallel to the rotational axis so that it is possible that the loading and unloading device cooperates with different rotors. Furthermore, the loading and unloading device comprises an actuator. By the actuator it is possible to feed a new probe from the outside towards the rotational axis to a mount of the rotor and in opposite direction to remove a probe that has been completely centrifuged from a mount in radial direction from the rotational axis of the rotor.
DE 10 2012 201 717 A1, corresponding to US 2015/0031521 A1, discloses a centrifuge, wherein a plurality of modules each comprise a rotor. The rotor comprises a horizontal rotational axis and forms a trough-shaped accommodation. The longitudinal axis of the accommodation has an orientation parallel to the rotational axis and comprises a U-shaped cross-section with slightly diverging side legs of the U. The rotational axis runs approximately in the middle of the U and has an orientation vertical to the plane of extension of the U. It is possible that a plurality of probe vessels are arranged and held one behind another in the direction of the rotational axis in the accommodation. Longitudinal axes of probe channels of a plurality of probe vessels are arranged parallel to each other in a common plane which has an orientation radial to the rotational axis. The modules comprise a rotational position sensor for sensing the rotational position of the accommodation. For the loading of probes into the accommodation as well as for the removal of probes from the accommodation after the centrifugation the accommodation is moved into a loading and unloading position under use of the signal of the rotational position sensor. In the loading and unloading position the longitudinal axes of the probe channels have an orientation parallel to the gravitational acceleration. A centrifugation is here accomplished with rotational speeds of more than 3,000 revolutions/min with the intention that an oscillating component of the acceleration acting upon the probes due to the gravitational acceleration builds a disturbance with an influence of less than one percent. By a balancing device comprising a balancing mass it is possible to remove any unbalanced mass of the rotor. Preferably, the probe carriers to be centrifuged are so called “gel cards” which comprise a plurality of probe channels. It is intended that the probe carrier is held at the accommodation by a latching means. For the provision of a small constructional space of the rotor it is possible that the probe carriers are arranged with a distance from the rotational axis being sufficiently small such that an end of a probe channel is located on the rotational axis. It is possible that the loading and/or unloading is provided by gripping tools of a loading automatic unit or by means of a pipetting device. Here, the loading and unloading is performed in the loading and unloading position of the accommodation with the introduction of the probe or the probe carrier from above between the side legs of the U-shaped accommodation and removal of the probe or the probe carrier after the centrifugation also in upper direction.
EP 2 835 178 A1 discloses a centrifuge which is used for washing of microtiter plates. In the centrifuge the microtiter plates are rotated around a horizontal rotational axis. In order to clean or wash the microtiters the openings of the microtiter plates have an orientation in radial outer direction such that the centrifugal force acting upon a fluid in the microtiter plates forces the fluid out of the microtiter plates. The centrifuge is driven with a number of revolutions of the drive of 5 to 3,000 revolutions per min. For another embodiment, the centrifuge is used for centrifuging reaction vessels or of blood for blood banks. In this case, the openings of the reaction vessels have an orientation in radial inner direction. Starting from a resting angular position, the reaction vessels are accelerated over an angle of 180° such that in a reversing angular position reached in this way at least a centrifugal acceleration of 1 g has been reached. Accordingly a leakage of the substance in the reaction vessel in downward direction is avoided. The document describes problems when accelerating microtiter plates with small recesses for the substances located in the reaction vessels because an undesired sloshing of the substance from one reaction vessel to an adjacent reaction vessel might occur caused by the acceleration. As a remedial measure, the document proposes to use an acceleration of 500 revolutions per min/sec up to 1,200 revolutions per min/sec.
Further prior art is known from US 2005/0026765 A1.